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简介：Thedynamicmicrocosmswereusedtoevaluatetheeffectofoilspillsonmicrobialecologicalsysteminmarinesedimentandtheenhancementofnutrientontheoilremoval.ThefunctionandstructureofmicrobialcommunitycausedbytheoilpollutionandphosphatedosageweresimultaneouslymonitoredbydehydrogenaseactivityassayandPCR-denaturinggradientgelelectrophoresis(DGGE)techniques.Theresultsindicatedthattheamountoftotalbacteriainalldynamicmicrocosmsdeclinedrapidlywithincubationtime.Thenumberofpetroleum-degradingbacteriaandtheactivityofsedimentdehydrogenaseweregraduallyenhancedbypetroleumintheoil-treatedmicrocosms,whiletheybothshowednoobviousresponsetophosphatedosage.Incomparison,phosphatespikedheterotrophicbacteriaandtheyshowedasignificantincreaseinamount.DGGEprofilesindicatedthatpetroleumdosagegreatlychangedcommunitystructure,andthebacteriabelongedtoclassDeltaproteobacteria,andphylaBacteroidetesandChlorobiwereenriched.Thisstudydemonstratedthatpetroleuminputgreatlyimpactedthemicrobialcommunitystructureandconsequentlythemarinesedimentpetroleum-degradingactivitywasenhanced.Phosphatedosagewouldmultiplyheterotrophicbacteriabutnotsignificantlyenhancethepetroleumdegradation.

简介：ThemoleculartransformationsofcarboxylicacidsinheavyacidicSLcrudebeforeandaftertrueboilingpointdistillationwereexaminedbyultra-highresolutionnegative-ionelectrosprayionization(ESI)Fouriertransformioncyclotronresonancemassspectrometry(FT-ICRMS).Theacidclass(heteroatomnumber),type(znumbers)andcarbonnumberdistributionswerepositivelycharacterized.Itwasfoundoutthatthetotalacidnumber(TAN)ofSLcrudedecreasedaftertrueboilingpointdistillation,andtheabundanceofO2classinmassspectrawasalsofoundtobereducedfrom67.6%to34.5%inSLTBPmixedcrudeasmeasuredbyMSspectra,indicatingtoapotentialcarboxylicaciddecomposition.However,itwasinterestingthatthecarboxylicacidstypedistributioninbothoilswasalmostthesamealthoughtheirrelativeabundanceinSLTBPmixedcrudeturnedtobemuchlower,suggestingthatvariouspetroleumcarboxylicacidtypeshavethesimilarthermaldecompositionreactionbehavior.Furthermore,foreachO2typeofacidsinSLTBPmixedcrude,theabundanceofcarboxylicacidswithcarbonnumberhigherthan35wasreducedgreatly,especiallyforthosewithcarbonnumberhigherthan60,themasspeaksofwhichwerenearlytotallyremoved,indicatingthatthelargecarboxylicacidmoleculesinheavyfractionsdecomposedmoresignificantlybecauseoflongerheatingtimeduringthetrueboilingpointdistillationprocess.Asaresult,thereductionofTANmaybecausedbythethermaldecompositionofcarboxylicacidsespeciallythosewithhighcarbonnumber,suggestingthatquickdistillationormuchlowerpressureisrequiredtoavoidthethermaldecomposition.